[clang] Fix assertion while parsing an invalid for loop

[cor3ntin]

Summary

with multiple declarations followed by a colon.

Fixes #63010

[cor3ntin]

revert ws changes

[shafik]

clang/lib/Parse/ParseStmt.cpp

2200

Can you explain why you removed this?

clang/test/Parser/cxx0x-for-range.cpp

67

Did you try dropping the ; at the end of this line to make sure it still does what we expect?

[cor3ntin]

clang/lib/Parse/ParseStmt.cpp

2200

The current diagnostics are pretty bad https://godbolt.org/z/z9odv3zjb - this fixes that

clang/test/Parser/cxx0x-for-range.cpp

67

yup, you think it's worth adding a test?

[shafik]

LGTM

clang/test/Parser/cxx0x-for-range.cpp

67

Yes, I feel like so many bugs could have been fixed by having better coverage that would have caught them when they were committed in the first place.

[cor3ntin]

Add tests for missing semi colons

clang/docs/ReleaseNotes.rst

- Match GCC's behavior for ``__builtin_object_size`` and
   ``__builtin_dynamic_object_size`` on structs containing flexible array
   members.
   (`#62789 <https://github.com/llvm/llvm-project/issues/62789>`_).
 - Fix a crash when instantiating a non-type template argument in a dependent scope.
   (`#62533 <https://github.com/llvm/llvm-project/issues/62533>`_).
 - Fix crash when diagnosing default comparison method.
   (`#62791 <https://github.com/llvm/llvm-project/issues/62791>`_) and
   (`#62102 <https://github.com/llvm/llvm-project/issues/62102>`_).
+- Fix assertion and quality of diagnostic messages in a for loop
+  containing multiple declarations and a range specifier
+  (`#63010 <https://github.com/llvm/llvm-project/issues/63010>`_).
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Bug Fixes to Attribute Support
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 - Fixed a bug where attribute annotations on type specifiers (enums, classes,
   structs, unions, and scoped enums) were not properly ignored, resulting in

clang/lib/Parse/ParseExprCXX.cpp

case ConditionOrInitStatement::ForRangeDecl: {
     // We're not actually in a for loop yet, so 'break' and 'continue' aren't
     // permitted here.
     assert(FRI && "should not parse a for range declaration here");
     SourceLocation DeclStart = Tok.getLocation(), DeclEnd;
     ParsedAttributes DeclSpecAttrs(AttrFactory);
     DeclGroupPtrTy DG = ParseSimpleDeclaration(
         DeclaratorContext::ForInit, DeclEnd, attrs, DeclSpecAttrs, false, FRI);
     FRI->LoopVar = Actions.ActOnDeclStmt(DG, DeclStart, Tok.getLocation());
-    assert((FRI->ColonLoc.isValid() || !DG) &&
-           "cannot find for range declaration");
     return Sema::ConditionResult();
   }
 
   case ConditionOrInitStatement::ConditionDecl:
   case ConditionOrInitStatement::Error:
     break;
   }
 

clang/lib/Parse/ParseStmt.cpp

StmtResult Parser::ParseForStatement(SourceLocation *TrailingElseLoc) {
   if (!getCurScope()->isContinueScope())
     getCurScope()->AddFlags(Scope::BreakScope | Scope::ContinueScope);
 
   // Parse the third part of the for statement.
   if (!ForEach && !ForRangeInfo.ParsedForRangeDecl()) {
     if (Tok.isNot(tok::semi)) {
       if (!SecondPart.isInvalid())
         Diag(Tok, diag::err_expected_semi_for);
-      else
-        // Skip until semicolon or rparen, don't consume it.
-        SkipUntil(tok::r_paren, StopAtSemi | StopBeforeMatch);
     }
 
     if (Tok.is(tok::semi)) {
       ConsumeToken();
     }
 
     if (Tok.isNot(tok::r_paren)) {   // for (...;...;)
       ExprResult Third = ParseExpression();

clang/test/Parser/cxx0x-for-range.cpp

 #define FORRANGE(v, a) for (DECLVARWITHINIT(v) a)  // expected-note {{expanded from macro}}
 #define DECLAUTOVAR(v) auto v
 #define DECLVARWITHINIT(v) DECLAUTOVAR(v) =  // expected-note {{expanded from macro}}
   FORRANGE(i, a) {  // expected-error {{range-based 'for' statement uses ':', not '='}}
 
   }
 }
 }
+
+namespace GH63010 {
+void foo(int n) {
+    int a[] = {1, 2, 3, 4, 5};
+    for (auto x = n ? 1 : 2 : a); // expected-error {{expected ';' in 'for' statement specifier}} \
+                                  // expected-error {{expected expression}}
+    for (int i = 1; auto x = n ? 1 : 2 : a); // expected-error {{expected ';' in 'for' statement specifier}}
+}
+}

clang/test/Parser/objc-foreach-syntax.m

 MyList * el; 
      for (el in @"foo") 
     { LOOP(); }
 }
 @end
 
 
 static int test7(id keys) {
-  // FIXME: would be nice to suppress the secondary diagnostics.
   for (id key; in keys) ;  // expected-error {{use of undeclared identifier 'in'}} \
-                           // expected-error {{expected ';' in 'for' statement specifier}} \
-                           // expected-warning {{expression result unused}}
+                           // expected-error {{expected ';' in 'for' statement specifier}}
 }